(1) Field of the Invention
The field of the invention is digital video representation, more specifically, the present invention is related to a method and apparatus for reducing digital video frame frequency while maintaining temporal smoothness.
(2) Related Art
Video media consists of a series of still pictures or frames which are displayed in order and at a steady speed. A video decoder decompresses the pictures in a timely manner allowing each picture to be available for display at the correct time. If the decompression cannot be completed by that time, it becomes necessary to either degrade the quality of the picture so the decompression may be performed quickly or to skip that particular frame. Generally, when frames are dropped, the previously displayed frame remains visible on the display medium twice as long resulting in a visible pause in the video.
FIG. 1 is a process flow diagram illustrating an exemplary processing of an encoded video stream. Encoded video stream 101 is parsed in block 102. The parsed encoded video stream is then decoded in block 103 and reconstructed in block 104. If video processing is delayed, then one or more video frames are dropped in block 105. Otherwise, the reconstructed video picture is rendered for display in block 105.
When a frame is dropped to compensate for delay in the processing of a video stream as was described above, the human eye is able to detect the loss of that picture, particularly in areas with a high frequency of motion. With the migration from hardware decoders to software decoders, video such as movies which are difficult to decode may cause a software decoder to fall behind and consequently drop one or more video frames.
In order to reduce the possibility that the human eye will detect a stall when a frame is dropped, a method and an apparatus for reducing digital video frame frequency while maintaining temporal smoothness of the video sequence being displayed are desirable.